Various strategies have been developed to improve automotive fuel efficiency and emissions reduction. For example, emissions reduction has been achieved by employing catalysts in the catalytic converters, and developing automotive parts from lightweight materials has been implemented to reduce weight of vehicles. A plasma transferred wire arc (PTWA) coating application on an aluminum alloy cylinder bores has proven to offer several advantages besides weight reduction. For example, the PTWA coating on cylinder bores reduces weight, cost, and bore spacing when compared to an aluminum engine block with thick iron cylinder liners.
Other engine parts contribute to fuel inefficiency and hydrocarbon emissions. For example, inserts and cast-in reinforcements within the internal combustion cylinder are used to provide sufficient strength to various cylinder parts. For instance, a cast-in reinforcement is used at an area of the top ring groove on a piston. However, the reinforcement increases the weight of the piston. Such reinforcements also add to noise, vibration, and cost. Other engine parts, such as the top land of the pistons, are known major sources of hydrocarbon emissions due to the crevice volume effect which also causes a significant efficiency penalty. Decreasing the crevice volume effect translates into improved fuel efficiency and lower hydrocarbon emissions. Therefore, there has been a long felt need to develop additional methods for reducing automotive emissions and increasing fuel efficiency.